1. Field of the Invention
This invention relates to a shielded wire-connecting structure which is used in an electric car or the like, and causes electromagnetic waves, transmitting along a shielded wire, to escape to the exterior, and also to block electromagnetic waves from the exterior so as to eliminate adverse effects of such electromagnetic waves on an equipment.
2. Related Art
Many equipments, such as a motor, are mounted on a vehicle (serving as a mobile structure) such as an automobile, and adverse effects of electromagnetic waves, generated from these equipments and wires, have now been at such a level that these effects can not be ignored. Particularly, adverse effects of electromagnetic waves, generated from large-current/high-voltage equipments, have become a problem. Therefore, the equipments and wires have been protected from electromagnetic interference by the use of a suitable method such as an electromagnetic shielding method although the countermeasures are different depending on the source of generation of electromagnetic waves and the kind of electromagnetic waves.
A wire having a shielding layer provided around its conductor, that is, a so-called shielded wire (or shielded cable), has been extensively used as a wire for supplying electric power to an on-vehicle equipment and also as a wire for transmitting and receiving signals. Particularly, a wire, having a thin design for lightweight purposes, is liable to be affected by electromagnetic waves, and a shielded wire has been used as such a wire.
FIG. 6 is one example of the art related to a structure of connecting a shielded wire of this kind shown in Unexamined Utility Model Publication Hei. 6-58560. This shield connector 100 includes a shielded wire 122, a metal terminal 115 of a cylindrical shape press-fastened to an end portion of the shielded wire 122, and an insulative connector housing 101 having a terminal receiving chamber 106.
The shielded wire 122 includes a conductor 122a provided at a center or axis thereof, a braided wire 122c provided around the conductor 122a through an inner insulating covering 122b, and an outer insulating sheath 122d forming an outermost layer. The metal terminal 115 is a so-called round pin formed by cutting a material of copper or a copper alloy. An electrical contact portion 117, having a bolt hole 117a, is formed at a front half of this metal terminal 115, while a wire connection portion 119, having a conductor insertion hoe 119a, is formed at a rear half thereof, and the two portions 117 and 119 are separated from each other by a partition wall 116 formed at a central portion of the metal terminal. An equipment-side terminal 127, press-fastened to a power connection cable 126 of an on-vehicle equipment, is fastened to the electrical contact portion 117 by a fastening bolt 130.
An end portion of the conductor 122a, exposed by removing the inner insulating covering 122b, is inserted into the conductor insertion hole 119a in the metal terminal 119, and is fixedly connected to the wire connection portion 119 by press-deforming this wire connection portion 119. A waterproof rubber plug 131 is fitted on an end portion of the braided wire 122c exposed by removing the outer insulating sheath 122d. A rubber plug holder 132 is fitted on the insulated wire, and is disposed at a rear side of the waterproof rubber plug 131. A connecting member 112 of an electrically-conductive nature is provided at the front side of the waterproof rubber plug 131, and is held in contact with the braided wire 122c. 
The connector housing 101 includes a cylindrical housing body 105, a shield shell 110 which is integrally molded in the housing body 105, and serves also as a grounding contact, and a flange portion 111 formed on and around an outer surface of the shield shell 110.
The housing body 105 has the terminal receiving chamber 106 having open opposite ends, and an outer wall of the housing body 105 is divided into a front half reduced-thickness portion and a rear half thickened portion, with a stepped portion formed at the boundary between the reduced-thickness portion and the thickened portion. The flange portion 111 is formed at the stepped portion over an entire periphery thereof, and is disposed perpendicularly to the outer wall.
The shield shell 110 has a generally L-shape or inverted L-shape as a whole, and includes a cylindrical tubular portion 110a, and a flange 110b extending generally perpendicularly from one end of the tubular portion 110a. The tubular portion 110a is integrally molded in the outer wall of the housing body 105 as described above. A distal end portion of the tubular portion 110a is resiliently contacted with the connecting member 112 resiliently supported on the waterproof rubber plug 131. The flange 110b for grounding purposes is exposed at the front side of the flange portion 111, and is held between a casing 125 and the flange portion 111.
The casing 125 is an electrically-conductive wall portion of the on-vehicle equipment such as a motor, and this casing 125 has a mounting hole 125a for the connector housing 101, and also has bolt holes 125b for the flange portion 111. The flange 110b of the shield shell 110 is held between the casing 125 and the flange portion 111, and then bolts 121 (serving as fastening members) are inserted respectively into the bolt holes 125b, and by doing so, the flange 110b and the casing 125 are held in contact with each other, thereby connecting the shielded wire 122 to the ground.
Another conventional example is a shielded wire-connecting structure using the fitting connection between male and female connectors Unexamined Japanese Patent Publication 2002-117947. In this conventional example, the connection of wire to a base wall for grounding purposes can be effected stably without incurring a permanent set, wear, etc., of a resilient contact portion, and a good shielding performance can be maintained, and also the shielding performance can be enhanced. A shield shell, joint terminals, an outer housing and a flange portion are formed of a non-magnetic material having electrical conductivity. The joint terminal is provided in contact with a connector entry-side inner wall surface of the outer housing, the shield shell is provided at the male connector, and the shield shell is connected at one side portion to braided wires of shielded wired, and is connected at the other side portion to the joint terminals, and the flange portion of the outer housing is fixedly connected by bolts to a electrically-conductive connector mounting wall of an equipment.
With respect to other conventional examples, there is known a structure in which a shield connector is covered with an electrically-conductive cover, and an electrically-conductive grommet is mounted on a distal end portion of a shielded wire in intimately-contacted relation thereto, and with this construction the connection of the shielded wire can be effected easily, and a waterproof performance is enhanced as shown in Unexamined Japanese Patent Publication Hei. 7-193966. There is also known a structure in which shielded wires, introduced from the exterior via respective grommets, are connected to a non-waterproof joint connector located within an auxiliary equipment box of a sealed structure, and with this construction the processing of the shielded wires can be effected easily as shown in Unexamined Japanese Patent Publication 2000-184556.
However, the above conventional shielded wire-connecting structures have the following problems to be solved.
In the first conventional example, when a plurality of shielded wires 122 were to be connected to the equipment, the casing 125 was required to have a large area to which the flange 110b of the shield shell 110 was to be connected, and therefore there was encountered a problem that the shield connector 100 could not be mounted on the casing.
And besides, the metal terminal 115, having the electrical contact portion 117 at one side of the partition wall 116 and the wire connection portion 119 at the other side of the partition wall, was received in the shield connector 100, and therefore the overall length of the shield connector 100 was large, and this invited a problem that the shield connector 100 had a large size. Particularly in the case of a multi-pole shield connector receiving a plurality of terminals, the number of component parts was large, and therefore the shield connector became unduly large, and in some cases, the shield connector could not be easily mounted on an equipment installed in a smaller space, for example, under a floor.
The flange 110b of the shield shell 110 and the bolt 130 were exposed to the outside of the casing 125, and therefore there was a fear that these were corroded by water, intruding from the exterior, and dew condensation, so that the shielding performance was adversely affected.
In the second conventional example, the connection between the shielded wire and the equipment was effected by the connector-connection between the male and female connectors, so that the connection could be effected with a one-touch operation. However, the connecting structure was complicated, and increased in size, so that the shield connector could not be easily mounted in a limited mounting space, thus inviting a problem that the efficiency of the mounting operation was low.
In the third conventional example, the waterproof grommet was mounted on each shielded wire, and therefore when a plurality of shielded wires were used, the shielded wire-connecting structure became complicated, thus inviting a problem that the structure became large in size.
In the fourth conventional example, the connector was connected to the end portions of the shielded wires introduced into the auxiliary box via the respective grommets, and therefore as in the first conventional example, there was encountered a problem that the number of the component parts was large, so that the shielded wire-connecting structure became large in size.